Thanks for the comment and the idea!
Maybe now I'm not an early game developer anymore :p
This is my first 7 days jam, I still can't figure out what can I do in one week at the start of the jam. I was focused in tweaking graphics at first, until I realize that I should be doing something else with my game at that time. Then at the end, I can't add the sounds because of the deadline.
But luckily because the gam still feels fun to play!